British Rail Class AM1

This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. Please help improve this article by introducing more precise citations. (November 2021) (Learn how and when to remove this message)

Class AM1 was allocated to the prototype AC electric multiple units, converted from fourth-rail DC electric stock in 1952 and used on the Lancaster/Morecambe/Heysham route. This route had been electrified by the Midland Railway at 6.6 kV, 25 Hz AC. These were withdrawn in 1952 and the service reverted to steam haulage. The line voltage was changed to 6.6 kV at 50 Hz in 1953 and the AM1s were introduced. Thus was a test to see if power could be drawn from the National Grid rather than railway owned power stations. The AM1s were fitted with mercury arc rectifiers but one was later converted to a solid state rectifier as a test. The stock was maintained at Meols Cop works near Southport.^{[citation needed]}

The line was closed to passengers and the stock withdrawn in early 1966. Unlike classes AM2-AM11, which became TOPS Classes 302–311, class AM1 was withdrawn before it could take its place in the system as class 301. However, it was the success of these tests that contributed to the decision to choose 25 kV AC overhead electrification as standard in Great Britain outside the Southern Region.